JPS58201731A - 2,4-dimethyl-(4'-(trans-4"-alkylcyclohexyl)cyclohexen-1'-yl) benzene - Google Patents

Abstract

NEW MATERIAL:A compound of formula I (R is H or 1-10C alkyl). EXAMPLE:2,4-Dimethyl-[4'-(trans-4''-pentylcyclohexyl)cyclohexen-1'-yl] benzene. USE:Useful as a component constituting liquid crystal compositions, having a wide nematic temprature range and a low viscosity, and capable of exhibiting the nematic liquid crystal phae in a wide temperature range including room temperature. PROCESS:2,4-Dimethylbromobenzene of formulaII is reacted with metallic magnesium to give a compound, which is then reacted with a 4-(trans-4'-alkylcyclohexyl)cyclohexanone to afford a compound of formula III. The resultant compound of formula III is then dehydrated with potassium hydrogensulfate to give the aimed compound of formula I .

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel liquid crystal material that exhibits a liquid crystal phase over a wide temperature range and has low viscosity. , Liquid crystal display elements utilize the optical anisotropy and dielectric anisotropy of liquid crystal materials, but the display method uses Tl.
There are various types such as 1 type, DB type, guest-host type, DAFT, and White-Tiller type, and each type requires different properties of the liquid crystal material used. For example, depending on the type of display element, a liquid crystal material with a positive dielectric anisotropy ΔC of 1, a negative dielectric anisotropy ΔC, or a liquid crystal material with a value in between Hiroshichi may be suitable. However, in any case, the liquid crystal materials used exhibit a liquid crystal phase over the widest possible temperature range, and are resistant to moisture, heat,
It must be stable against air, light, etc. At present, there is no single compound that satisfies all of these conditions, and the current state of affairs is to mix several types of liquid crystal compounds, metals, and non-liquid crystal compounds to obtain compounds that can withstand practical use.

Nearest, there is a wide range of temperatures in -2'O
There is a demand for liquid crystal display elements that can operate from high temperatures (about 8.0°C) to high temperatures (around 8.0°C). 9. There is a growing need for low viscosity liquid crystal materials.

The unexploded compound provides a novel liquid crystal compound that is important as a component constituting a liquid crystal composition that satisfies such requirements. 1.

That is, the present invention provides 2,4-dimethyl-(4'-() lance-
4'-Furkylcyclohexyl) cyclohexane-1
'-yl]benzene.

The compound of formula (1) of the present invention has a very wide nematic temperature range (for example, when R is 07H15, from below room temperature to 71.8°C) and has a low viscosity.

To the best of my knowledge, this compound is the first.

Next, the method for producing the compound of the present invention will be described.

First, commercially available 2,4-dimethylbromobenzene (9o%)
was reacted with metallic magnesium to form 2,4-dimethylbenzenemagnesium bromide, and tLl in 47():1
7n-4'-alkylcyclohexyl)cyclohexanone to give 2,4-1dimethyl-(4'-()lanth-41-alkylcyclohexyl)cyclohexan-11-ol]benzene (It).

Next, this was dehydrated with potassium hydrogen sulfate to produce 2.4 dimethyl (4'-() lance-41-alkylcyclohexyl).
Cyclohexene-1'-1]benzene (1) is obtained.

The chemical formula for the above is as follows.

Hereinafter, the production method and usage examples of the compounds of the present invention will be explained in more detail with reference to Examples.

Example h [z, 4"-dimethyl □-・(4'-() lance-41-pentylcyclohexyl) □ Production of clohexene-1'-1]benzene] Commercially available ゛'2,4-dimethylbromo Benzene (904)
25f (0,134 mol) of tetrahydrofuran 30
-Metal magnesium 3', 2'f (α134"
mol) in a nitrogen stream to give 2,4-dimethylbe/zenmagnesium bromide. After the solution becomes homogeneous, convert the key 5- to 4-(trans-4'-pentylcyclo
- Add dropwise a solution of cyclohexanone 27f (0108 mol) dissolved in tetrahydrofuran so that the reaction temperature does not exceed 30°C. After dropping, reflux for 2 hours, then add 3N-salt #11100-, then n-
Extract with Hebuta/3.50-. The oil layer is washed with water until the washing liquid becomes neutral, and the solvent is distilled off under reduced pressure. The remaining oil is 2.4-
Dimethyl-(4'-()lans-41-pentylcyclohexyl)cycloh-V-+no-1'-ol]benzene was added with 10F potassium hydrogen sulfate and dehydrated at 200°C for 2 hours under a nitrogen atmosphere. After cooling, 100 ml of n-hebutane is added, potassium hydrogen sulfate is separated with F, and the heptane layer is washed until the liquid becomes neutral. Rinse with water until Then, the solvent was distilled off under reduced pressure, and the residue was recrystallized from n-hebutane to obtain the desired 2,4-dimethyl-(4'
-() Lance-V-pen 6-tylcyclohexyl)cyclohexen-1'-yl]benzene. Vacuum distill this and 2
By taking a fraction of Hf at 43°C, even higher purity can be obtained. Yield 21.7 f 0 O of this stuff
-N point was below room temperature, and N-1 point was 78.1°C.

In the above procedure, 4-(trans-4I-alkylcyclohexyl)cyclohexanone having a different alkyl group was used instead of 4-(trans-4'-pentylcyclohexyl)cyclohexano/, but the following procedure was performed in exactly the same manner. A compound was prepared.

2,4-dimethyl-(trans-4'-cyclohexylcyclohexyl)ben/zene, 2,4-dimethyl-(4'-()trans-41-
methylcyclohexyl)cyclohexen-1'-yl]
Benzene, 2,4-dimethyl-(4'-()lance-
7-41-ethylcyclohexyl)cyclohexene-1'-
yl]benzene, 2,4-dimethyl-(4'-() lance-4'-propylcyclohexyl)cyclohexen-1'-yl]benzene, 2,4-dimethyl-(4'
-() lance-41-butylcyclohexyl)cyclohexen-1'-yl]benzene, 2,4-dimethyl-(
4'-()lance-41-hexylcyclohexyl)cyclohexen-1-yl]benzene, 2,4-dimethyl-[4'-()lance-4L-butylcyclohexyl)cyclohexen-11-yl]benzene, 2,
4-dimethyl-[4/=(trans-41-octylcyclohexyl)cyclohexen-1'-yl]benzene, 2,4-dimethyl-(4'-()trans-4'-nonylcyclohexyl)cyclohexene-1'- yl]benzene, 2,4-dimethyl-(4'-()lans-8-41-decylcyclohexyl)cyclohexene-1'-
] benzene.

Example 2 (Application example) Trans-4-pentylcyclohexanecarboxylic acid 4/
-Fluorophenyl ester 15 parts trans-4-heptylcyclohexanecarboxylic acid c? -Fluorophenyl ester 15 parts trans-4-()trans-4'-probyldichromehexyl)cyclohexanecarboxylic acid-
4'-fluorophenyl ester 5-trans-
The N-1 point of the liquid crystal composition consisting of 5 parts of 4-()lance-4'-pentylcyclohexyl)cyclohexanecarboxylic acid-4'-fluorophenyl ester is 59.
6℃, dielectric anisotropy value Δ1 is +2.2, optical anisotropy value Δn
has a viscosity of 1 7.7 cp at 0.064.20°C. This liquid crystal composition was sealed in a TNN sill twisted nematic cell with a cell thickness of 10 μm, and the operating threshold voltage was 2.33V and the saturation voltage was 3.28V.

9- 75 parts of this liquid crystal composition and 2 which is one of the compounds of the present invention
, 4-dimethyl-(4'-()lance-4#-pentylcyclohexyl)cyclohexen-1'-yl] The N-1 point of a liquid crystal composition consisting of 25 parts of benzene is 60.1 u.
, dielectric anisotropy value △1 is +1.8, optical anisotropy value Δn F
i, viscosity at 0.07420°C is 24. It is Ocp.

The threshold voltage is 2.55 V, the saturation voltage is 3.55 V, and a low viscosity liquid crystal composition can be produced.

that's all Patent applicant: Chisso Corporation Agent: Patent Attorney Yatabe Sasai Same as above Katsuhiko Nonaka 10-

Claims (1)

[Scope of Claims] (In the above formula, R represents hydrogen or an alkyl group having 1 to 10 carbon atoms) 2,4-dimethyl-(4'-()2-41-alkylcyclohexyl)cyclohexene-1 /
−il] benzene. (In the above formula, R represents hydrogen or an alkyl group having 1 to 10 carbon atoms) 2,4-dimethyl-(4'-() lance-
4'-Alkylcyclohexyl)cyclohexene-71
A liquid crystal composition characterized in that it has at least one property.